R5+100-500+1.4x or R7+100-500?

I just completed my third my third comparison shot session for collecting images from the label on the power pole near my house. I have made several small refinements in technique for each of the three test shooting days.

There is was a great deal of forum interest/attention to the use of the R5/ RF 100-500 with the 1.4X TC vs the R7 using the same RF 100-500 lens. These pictures are of a label that is over 100 feet from the shooter and all pictures are made from same shooting location.

Using the R7 and the RF 100-500 with no TC resulted in 6000 pixels on the label

R7 with RF 100-500 @ 500mm (note that is a shadow from a nearby wire block left side of image)

Using the R5 and the RF 100-500 with no TC resulted in 3000 pixels on the label

Using the R5 and the RF 100-500 with 1.4X TC and 1.96 more pixels on the label resulted in

R5 using as 700mm/f10 equivalent lens with the RF-100-500 and 1.4X TC

Using the R5 and the RF 100-500 using 451mm FL with 2X resulted in 6000 pixels on the label

R5 using as 904mm/f16 lens with the RF 100-500 and 2X TC

Note: the 902mm was the FL because the zoom got bumped changing the 1.4X TC with the 2X TC. Also note the increased number of pixels on the label from using the 2X TC rather than the 1.4X TC.

To judge the images above for detail you should adjust them to be side by side and same physical size on your large computer screen. The R7/RF100-500 without TC and R5/RD100-500 1.4X TC are best compared side side and adjust to make both the same size.

Despite being a f2X TC resulting in the aperture to be f13 at the 904mm the image it generations is pretty competitive with R7 image using only the bare RF 100-500